The present invention relates to a method of and an apparatus for forming image(s) comprising a hard disk controller that operates a plurality of hard disk drives (HDD""s) in parallel, to rapidly read/write enormous amounts of data, such as image data processed with an electronic filing system.
It has been know that storage device arrays including a plurality of storage devices such as HDD""s that are operated in parallel, allow fast reading/writing of data. A conventional storage device array has an array controller, which works as a control section, and which may be provided in a form of an expansion board connected to a bus in a personal computer.
The array controller in the form of an expansion board is inserted in an expansion slot of the personal computer, and connected to a group of storage devices to be controlled. The array controller controls the group of storage devices according to instructions sent from the personal computer. The array controller reads/writes blocks of data from/into different drives of the group of storage devices, while changing the drive to be read/written from/into block by block.
FIG. 19 illustrates an example of how a conventional array controller (hard disk controller) writes data into a plurality of HDD""s. In this example, 96 kilobytes (KB) of data are written into four HDD""s, block by block, each block having a size of 16 KB.
As shown in FIG. 19, the data are divided and written into the different discs in sequence starting from the first 16 KB block of data into a disc 0. After the fourth block is written into a disc 4, the next block is written into the disc 0, and so on. In general, HDD""s are each provided with a data buffer having a capacity of 16 KB or more such that data to be transferred can be stored in the data buffer first before they are written into the disk. Accordingly, data can be written into different HDD""s in sequence, such that a block of data is written into an HDD while another block of data is being transferred to another HDD from a data buffer inside. As a result, fast data transfer can be achieved.
Such a method of dividing data into different HDD""s is disclosed in the Japanese Laid Open Paten Application No. 10-326154 titled xe2x80x9cArray controller and data serverxe2x80x9d. However, the configuration of the array controller disclosed in this application is rather complex. That is, a special central processing unit (CPU) is required for the array controller, and it is required that hard disks are specially controlled with software that analyzes commands on the bus.
Some of the present day image formation apparatuses such as digital copiers are provided with a plurality of HDD""s. Development of hard disk controllers to be used in such image formation apparatuses are in great demand, the hard disk controllers which can transfer image data to the plurality of HDD""s fast and control the HDD""s efficiently.
It is an object of the present invention to provide a method of and an apparatus for forming image(s) comprising a simply configured hard disk controller that can transfer image data to a plurality of HDD""s fast, and control the plurality of HDD""s efficiently as a single HDD.
It is another object of the invention to provide a method of and an apparatus for forming image(s), comprising a hard disk controller, which can specify an HDD out of a plurality of HDD""s, the HDD in which a malfunction has occurred.
It is still another object of the invention to provide a method of and an apparatus for forming image(s), comprising a hard disk controller, which can specify an HDD out of a plurality of HDD""s, the HDD in which a decrease in its transfer rate has been caused.
It is yet anther object of the invention to provide a method of and an apparatus for forming image(s), comprising a hard disk controller, which can specify an HDD out of a plurality of HDD""S, the HDD in which a decrease in its transfer rate has been caused by factors other than emergent disturbances such as vibrations.
The image formation apparatus according to the present invention comprises an input unit which acquires an image data, a central processing unit which controls an overall operation of the apparatus, a plurality of hard disk drives which store the image data, a memory which stores at least one page of the image data, a direct memory access controller which controls reading/writing of the image data from/into the memory, a hard disk controller which sends/receives the image data to/from the direct memory access controller when reading/writing the image data from/into the memory and controls reading/writing of image data from/into the hard disk drives, and an image formation unit which forms an image based on the image data. In the method of and apparatus for image formation according to the present invention, the hard disk controller controls setting of parameters, issuance of commands, and reading of statuses for the hard disk drives substantially at the same time, divides the image data into a plurality of pieces, and executes direct memory access transfer of the pieces of the image data to the hard disk drives substantially at the same time.
Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.